Expandable wavelength-selective and loss-less optical add/drop system
First Claim
1. An expandable optical add/drop system includingan optical add/drop multiplexer element having an input port and an output port, said input port for receiving a multi-wavelength optical signal having individual optical signals of different wavelengths, said multiplexer element further including a drop path for carrying at least one of said individual optical signals dropped from said multi-wavelength optical signal, and an add path for carrying at least one optical signal of a particular wavelength to be added to said multi-wavelength optical signal, and a through path coupled between said input port and said output port, wherein a common portion is defined by portions of each of said add, drop and through paths such that said common portion is capable of being used for adding and dropping individual optical signals and for carrying said multi-wavelength signal,a passive optical signal splitting device coupled to said drop path for receiving said at least one individual optical signal to be dropped from said multi-wavelength optical signal, and for distributing said at least one individual optical signal via plural output ports, anda tunable optical filter coupled to one of said plural output ports, said tunable optical filter being operable to selectively pass only one individual optical signal of a particular wavelength,said common portion including a wavelength-selective apparatus with integrated amplification for use in the expandable add/drop system, the apparatus comprising:
- at least one wavelength selective element disposed in a wavelength-selective path between said input port and said output port;
an optically amplifying rare earth-doped fiber section integrated with said wavelength-selective path, said optically amplifying rare earth-doped fiber section includinga first segment coupled between said input port and said at least one wavelength selective element, anda second segment coupled between said at least one wavelength selective element and said output port; and
a source of pump light coupled to and operable to pump said optically amplifying rare earth-doped fiber section,wherein said at least one wavelength selective element is adapted to selectively reflect said at least one individual optical signal to be dropped from said multi-wavelength optical signal across said drop path via said first segment,wherein other said plural output ports are adapted to receive additional passive optical signal splitting devices and tunable optical filters in a tree configuration for selectively passing other reflected individual optical signals dropped from said multi-wavelength optical signal.
6 Assignments
0 Petitions
Accused Products
Abstract
An expandable optical add/drop system according to the present invention includes an optical add/drop multiplexer with an integrated amplification and wavelength-selective fiber path and passive optical couplers for selectively adding and dropping wavelengths from a multi-wavelength signal, such as a wavelength division multiplexed optical signal. One or more fiber gratings are disposed along the length of a rare earth-doped optical fiber or between segments of the rare earth-doped optical fiber so that at least one grating is used for reflecting each optical signal that is to be added to or dropped from the multi-wavelength optical signal. By using this configuration, appropriate amplification is provided to compensate for specific losses in the add, drop, and through paths for existing and future add/drop service.
86 Citations
29 Claims
-
1. An expandable optical add/drop system including
an optical add/drop multiplexer element having an input port and an output port, said input port for receiving a multi-wavelength optical signal having individual optical signals of different wavelengths, said multiplexer element further including a drop path for carrying at least one of said individual optical signals dropped from said multi-wavelength optical signal, and an add path for carrying at least one optical signal of a particular wavelength to be added to said multi-wavelength optical signal, and a through path coupled between said input port and said output port, wherein a common portion is defined by portions of each of said add, drop and through paths such that said common portion is capable of being used for adding and dropping individual optical signals and for carrying said multi-wavelength signal, a passive optical signal splitting device coupled to said drop path for receiving said at least one individual optical signal to be dropped from said multi-wavelength optical signal, and for distributing said at least one individual optical signal via plural output ports, and a tunable optical filter coupled to one of said plural output ports, said tunable optical filter being operable to selectively pass only one individual optical signal of a particular wavelength, said common portion including a wavelength-selective apparatus with integrated amplification for use in the expandable add/drop system, the apparatus comprising: -
at least one wavelength selective element disposed in a wavelength-selective path between said input port and said output port; an optically amplifying rare earth-doped fiber section integrated with said wavelength-selective path, said optically amplifying rare earth-doped fiber section including a first segment coupled between said input port and said at least one wavelength selective element, and a second segment coupled between said at least one wavelength selective element and said output port; and a source of pump light coupled to and operable to pump said optically amplifying rare earth-doped fiber section, wherein said at least one wavelength selective element is adapted to selectively reflect said at least one individual optical signal to be dropped from said multi-wavelength optical signal across said drop path via said first segment, wherein other said plural output ports are adapted to receive additional passive optical signal splitting devices and tunable optical filters in a tree configuration for selectively passing other reflected individual optical signals dropped from said multi-wavelength optical signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. An expandable optical add/drop system including
an optical add/drop multiplexer element having an input port and an output port, said input port for receiving a wavelength division multiplexed (WDM) optical signal having individual optical channels of different wavelengths, said multiplexer element further including a drop path for carrying at least one of said individual optical channels dropped from said WDM optical signal, and an add path for carrying at least one optical channel of a particular wavelength to be added to said WDM optical signal, and a through path coupled between said input port and said output port, wherein a common portion is defined by portions of each of said add, drop and through paths such that said common portion is capable of being used for adding and dropping individual optical channels and for carrying said WDM optical signal, a passive optical signal splitting device coupled to said drop path for receiving said at least one individual optical channel to be dropped from said WDM optical signal, and for distributing said at least one individual optical channel via plural output ports, and a tunable optical filter coupled to one of said plural output ports, said tunable optical filter being operable to selectively pass only one individual optical channel of a particular wavelength, said common portion including a wavelength-selective apparatus with integrated amplification for use in the expandable add/drop system, the apparatus comprising: -
at least one wavelength selective element disposed in a wavelength-selective path between said input port and said output port; a rare earth-doped optical fiber section integrated along said wavelength-selective path between said input and output ports for optically amplifying said WDM optical signal; and a source of pump light coupled to and operable to pump said rare earth-doped optical fiber section, wherein said at least one wavelength selective element is adapted to selectively reflect said at least one individual optical channel to be dropped from said WDM optical signal across said drop path via said first segment, wherein other said plural output ports are adapted to receive additional passive optical signal splitting devices and tunable optical filters in a tree configuration for selectively passing other reflected individual optical channels dropped from said WDM optical signal. - View Dependent Claims (13, 14)
-
-
15. An expandable optical add/drop system including
an optical add/drop multiplexer element having a first and second directional optical transfer device, said first directional optical transfer device being coupled to receive a multi-wavelength optical signal having individual optical signals of different wavelengths, a passive optical signal splitting device coupled to a drop port of said first directional optical transfer device for receiving at least one individual optical signal to be dropped from said multi-wavelength optical signal, and for distributing said at least one individual optical signal via plural output ports, and a tunable optical filter coupled to one of said plural output ports, said tunable optical filter being operable to selectively pass only one individual optical signal of a particular wavelength, a wavelength-selective apparatus with integrated amplification for use in the expandable optical add/drop system, comprising: -
at least one wavelength selective element disposed in a wavelength selective path between said first and second directional optical transfer devices; an optically amplifying rare earth-doped fiber section integrated with said wavelength-selective path, said optically amplifying rare earth-doped fiber section including a first segment coupled between said first directional optical transfer device and said at least one wavelength selective element, and a second segment coupled between said at least one wavelength selective element and said second directional optical transfer device; and a source of pump light coupled to and operable to pump said rare earth-doped fiber section, wherein said at least one wavelength selective element is adapted to selectively reflect said at least one individual optical signal to be dropped from said multi-wavelength optical signal via said drop port, and wherein other said plural output ports are adapted to receive additional passive optical signal splitting devices and tunable optical filters in a tree configuration for selectively passing other reflected individual optical signals dropped from said multi-wavelength optical signal. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
-
-
27. An expandable optical add/drop system including
an optical add/drop multiplexer element having a first and second optical circulator, said first optical circulator being coupled to receive a wavelength division multiplexed (WDM) optical signal having individual optical channels of different wavelengths, a passive optical signal splitting device coupled to a drop port of said first optical circulator for receiving at least one individual optical channel to be dropped from said WDM optical signal, and for distributing said at least one individual optical channel via plural output ports, and a tunable optical filter coupled to one of said plural output ports, said tunable optical filter being operable to selectively pass only one individual optical channel of a particular wavelength, a wavelength-selective apparatus with integrated amplification for use in the expandable optical add/drop system, comprising: -
at least one wavelength selective element disposed in a wavelength selective path between said first and second optical circulators; a rare earth-doped optical fiber integrated along said wavelength-selective path for optically amplifying said WDM optical signal; and a source of pump light coupled to and operable to pump said rare earth-doped optical fiber, wherein said at least one wavelength selective element is adapted to selectively reflect said at least one individual optical channel to be dropped from said WDM optical signal via said first optical circulator, and wherein other said plural output ports are adapted to receive additional passive optical signal splitting devices and tunable optical filters in a tree configuration for selectively passing other reflected individual optical channels dropped from said WDM optical signal. - View Dependent Claims (28, 29)
-
Specification